It is a bio film made of waste, proteins and general funk. Increased surface agitation will help mix it back into the water and increased PWCs will help remove it. To get rid of it right now you can use paper towels... Gently lay them flat on the surface then remove and toss, repeat as needed.
mohican said:Well said! I just had a post yesterday and learned the same thing. I haven't done it yet,but i need to aim spray bars closer to surface. Good Luck!